Aqueous compositions containing stabilized enzymes

Abstract

Aqueous enzyme preparation stabilized with a salt of a lower molecular weight acid in the presence of alcohol.

What I claim is: 
     
       1. An aqueous-based enzyme containing composition wherein the enzymes have enhanced stability against loss of activity, the composition comprising on a weight basis: (a) from about 0 to about 55% of a surfactant selected from the group consisting of anionic and nonionic surfactants, and mixtures thereof;   (b) from about 0.006 to about 5% of an active enzyme selected from the group consisting of protease and alpha amylase enzymes, and mixtures thereof, said enzyme being provided in pure form or as incorporated within a commercial enzyme preparation comprising from about 2 to about 80% of said enzyme and from about 20 to about 98% of a carrier therefor;   (c) an enzyme stabilizer consisting essentially of on a weight basis of said composition: (i) from about 0.5 to about 15% of a salt of a lower molecular weight organic acid selected from the group consisting of alkali metal, ammonium and alkanol ammonium salts of formic, acetic, propionic, butyric, and valeric acids, and mixtures thereof, and   (ii) from about 1.0 to about 25% of an alcohol having the formula ROH wherein R is an alkyl having one to six carbon atoms, and     (d) from about 10 to about 90% water.   
     
     
       2. The composition of claim 1 wherein the carrier is selected from the group consisting of sodium chloride, sodium sulfate, calcium sulfate, glycerol, and combinations of same. 
     
     
       3. The composition of claims 1 or 2 wherein the alkanol ammonium is selected from the group consisting of monoethanolammonium, diethanolammonium and triethanolammonium. 
     
     
       4. The composition of claims 1 or 2 wherein the pH is from about 6 to about 10. 
     
     
       5. The composition of claims 4 wherein the percent by weight of water is from about 40% to about 90%. 
     
     
       6. The composition of claim 5 wherein the percent by weight of the enzyme is from about 0.006% to about 2.5%. 
     
     
       7. The composition of claim 6 wherein the percent by weight of the alcohol is from about 4% to about 10%. 
     
     
       8. The composition of claim 7 wherein the percent by weight of the surfactant is from about 5% to about 30%. 
     
     
       9. The composition of claim 8 wherein the percent by weight of the salt is from about 2% to about 6%. 
     
     
       10. The composition of claim 9 wherein the pH is from about 6 to about 9. 
     
     
       11. The composition of claim 10 wherein the enzyme is a proteolytic enzyme obtained from the Bacillus Substilis. 
     
     
       12. The composition of claim 11 wherein the salt is sodium acetate or sodium propionate. 
     
     
       13. The composition of claim 12 wherein the alcohol is ethanol. 
     
     
       14. The composition of claim 13 wherein the percent by weight of the surfactant is about 30%; and wherein the surfactant is a mixture comprised of about 33.3% by weight of an anionic surfactant and about 66.6% by weight of a nonionic surfactant. 
     
     
       15. The composition of claim 13 wherein the nonionic surfactant is an ethoxylated fatty alcohol having the formula RO--(CH 2  CH 2  O) n  H wher R is from 8 to 18 carbon atoms and n is an integer from 1 to 500. 
     
     
       16. The composition of claim 15 wherein the nonionic surfactant is a mixture of: a. the condensation product of 1 mole of an aliphatic alcohol having from 12 to 13 carbon atoms in either a straight or branched chain configuration, with an average of 6.5 moles of ethylene oxide; and   b. the condensation product of 1 mole of an aliphatic alcohol, having from 12 to 15 carbon atoms in either a straight or branched chain configuration, with 9 moles of ethylene oxide.   
     
     
       17. The composition of claim 16 wherein the nonionic surfactant mixture is comprised of about 50% by weight of component a and about 50% by weight of component b. 
     
     
       18. The composition of claim 17 further comprising by weight of the composition: a. from about 1% to about 10% of a solubilizing compound; and   b. from about 1% to about 75% of an isoparaffinic mixture of petroleum distallates having an average molecular weight of about 154.   
     
     
       19. The composition of claim 18 wherein the solubilizing agent is about 3%-6% by weight of the composition; wherein the isoparaffinic mixture of petroleum distallates is about 10%-40% by weight of the total composition and wherein the solubilizing agent is sodium xylene sulfonate.